Certain microporous structures can serve as valuable industrial catalysts. Several features of these structures make them particularly well suited for catalytic applications. For example, their high surface area to volume ratio provides a dense region of reactivity. Their heterogeneity with fluid reactants and products permits relatively easy recovery of the catalyst post-reaction. Furthermore, their microscopic structure provides for physical modulation of the reactants and products in addition to any chemical catalysis.
Some microporous structures, for example some molecular sieves, do not provide for chemical catalysis, but instead solely accomplish physical modulation of working fluids or solutions. Whether or not a microporous structure provides chemical catalytic functions in addition to physical structure, is also a function of the material from which the structure is made.
Most microporous structures cannot be constructed as such, but instead rely on a variety of complex chemical and mechanical formation mechanisms, including self-assembly. These mechanisms are exploited in known production methods, such as sol-gel. Unfortunately, because these production methods and formation mechanisms can operate only on materials with chemical structure, arbitrary materials cannot be formed into a selected microporous structure. Additionally, the catalytic mechanisms within microporous structures are complex and do not always directly relate to the catalytic functionality present in precursors. Thus, formation of a microporous structure capable of performing a desired catalytic function requires a suitable precursor that can chemically form the required structure while retaining a functional group capable of performing the desired catalytic function.
Zeolites are a well-known class of microporous structures. Zeolites are crystalline aluminosilicate minerals that form regular, porous structures. The building blocks of zeolites have the chemical structures illustrated in FIGS. 1 and 2. Typically, a zeolite comprises SiO4 structures, such as the SiO4 structure 100 shown in FIG. 1, bonded with AlO4 structures, such as the AlO4 structure 200 shown in FIG. 2, through shared oxygen atoms. The structure shown in FIG. 2 is not stable on its own, but appears within a crystal including SiO4 structures.
However, what is needed in the art is a system for and a method of engineering the catalytic behavior of a porous structure without having to rely on synthesis of precursors suitable for formation into the porous structure.